1. Field of the Invention
The present invention relates to a switch such as a seesaw type switch, a lever type switch or the like used in a power window switch or the like.
2. Description of the Related Art
There is a conventional seesaw type switch as shown by, for example, FIG. 25. FIG. 25 is a sectional view in a state of attaching a switch knob, showing a neutral holding structure the switch knob.
As shown by FIG. 25, according to a seesaw type switch 201, a switch knob 203 is axially supported by a knob attaching portion 207 of a switch case 205 pivotably around, for example, a pivoting center C and capable of operating pivoting movement. Therefore, when the switch knob 203 is operated to push to thereby pivot around the pivoting center C in the counterclockwise direction, power window of an automobile is operated to lower. Further, when the switch knob 203 is pulled up to thereby pivot around the pivoting center C in the clockwise direction, the power window is operated to lift.
Such a switch knob 203 is held by a neutral holding mechanism 209 at a neutral position at which the power window is not operated to lift or lower. That is, a spring containing portion 211 is provided in the switch case 205. A coil spring 213 is contained in the spring containing portion 211. A steel ball 215 is arranged at an upper end of the spring containing portion 211. The steel ball 215 is brought into elastic contact with a recessed portion 217 of the switch knob 203.
Therefore, by an urging force of the coil spring 213, the steel ball 215 is brought into elastic contact with the recessed portion 217 of the switch knob 203 and the switch knob 203 is held at the neutral position.
In operating the switch knob 203, the recessed portion 217 of the switch knob 203 can be moved relative to the steel ball 215 to thereby enable to pivot the switch knob 203. Further, after the switch knob 203 is operated to press or operated to pull up, when the switch knob 203 is detached, the switch knob 203 can automatically return to the neutral position of FIG. 25 by elastic contact of the steel ball 215 with the recessed portion 217.
In this way, by the neutral holding mechanism 209, the switch knob 203 can be held at the neutral position and the play of the switch knob 203 can be prevented.
However, according to the above-described structure, in integrating operation, there is constituted a procedure of containing the coil spring 213 in the spring containing portion 211, thereafter inserting the steel ball 215 thereinto, coating grease and integrating the switch knob 203 and therefore, there poses a problem that a number of integrating steps is large.
Further, according to the structure as shown in FIG. 25, there is a concern of bringing about a failure in step such as a failure in inserting the coil spring 213, detachment of the steel ball 215 or the like and there is a concern of bringing about trouble in operation of the switch knob 203.
Further, a number of parts of the coil spring 213, the steel ball 215 and the like is large and integration and parts control are complicated to thereby cause to increase cost.